Merge branch 'fg/submodule-clone-depth'

Allow shallow-cloning of submodules with "git submodule update".

* fg/submodule-clone-depth:
  Add --depth to submodule update/add

Documentation/git-submodule.txt

@@ -10,12 +10,12 @@ SYNOPSIS
 --------
 [verse]
 'git submodule' [--quiet] add [-b <branch>] [-f|--force] [--name <name>]
-	      [--reference <repository>] [--] <repository> [<path>]
+	      [--reference <repository>] [--depth <depth>] [--] <repository> [<path>]
 'git submodule' [--quiet] status [--cached] [--recursive] [--] [<path>...]
 'git submodule' [--quiet] init [--] [<path>...]
 'git submodule' [--quiet] deinit [-f|--force] [--] <path>...
 'git submodule' [--quiet] update [--init] [--remote] [-N|--no-fetch]
-	      [-f|--force] [--rebase] [--reference <repository>]
+	      [-f|--force] [--rebase] [--reference <repository>] [--depth <depth>]
 	      [--merge] [--recursive] [--] [<path>...]
 'git submodule' [--quiet] summary [--cached|--files] [(-n|--summary-limit) <n>]
 	      [commit] [--] [<path>...]
@@ -330,6 +330,12 @@ for linkgit:git-clone[1]'s `--reference` and `--shared` options carefully.
 	only in the submodules of the current repo, but also
 	in any nested submodules inside those submodules (and so on).
 
+--depth::
+	This option is valid for add and update commands. Create a 'shallow'
+	clone with a history truncated to the specified number of revisions.
+	See linkgit:git-clone[1]
+
+
 <path>...::
 	Paths to submodule(s). When specified this will restrict the command
 	to only operate on the submodules found at the specified paths.

git-submodule.sh

@@ -35,6 +35,7 @@ nofetch=
 update=
 prefix=
 custom_name=
+depth=
 
 # The function takes at most 2 arguments. The first argument is the
 # URL that navigates to the submodule origin repo. When relative, this URL
@@ -251,6 +252,7 @@ module_clone()
 	name=$2
 	url=$3
 	reference="$4"
+	depth="$5"
 	quiet=
 	if test -n "$GIT_QUIET"
 	then
@@ -273,7 +275,7 @@ module_clone()
 		mkdir -p "$gitdir_base"
 		(
 			clear_local_git_env
-			git clone $quiet -n ${reference:+"$reference"} \
+			git clone $quiet ${depth:+"$depth"} -n ${reference:+"$reference"} \
 				--separate-git-dir "$gitdir" "$url" "$sm_path"
 		) ||
 		die "$(eval_gettext "Clone of '\$url' into submodule path '\$sm_path' failed")"
@@ -350,6 +352,14 @@ cmd_add()
 			custom_name=$2
 			shift
 			;;
+		--depth)
+			case "$2" in '') usage ;; esac
+			depth="--depth=$2"
+			shift
+			;;
+		--depth=*)
+			depth=$1
+			;;
 		--)
 			shift
 			break
@@ -459,7 +469,7 @@ Use -f if you really want to add it." >&2
 				echo "$(eval_gettext "Reactivating local git directory for submodule '\$sm_name'.")"
 			fi
 		fi
-		module_clone "$sm_path" "$sm_name" "$realrepo" "$reference" || exit
+		module_clone "$sm_path" "$sm_name" "$realrepo" "$reference" "$depth" || exit
 		(
 			clear_local_git_env
 			cd "$sm_path" &&
@@ -736,6 +746,14 @@ cmd_update()
 		--checkout)
 			update="checkout"
 			;;
+		--depth)
+			case "$2" in '') usage ;; esac
+			depth="--depth=$2"
+			shift
+			;;
+		--depth=*)
+			depth=$1
+			;;
 		--)
 			shift
 			break
@@ -797,7 +815,7 @@ Maybe you want to use 'update --init'?")"
 
 		if ! test -d "$sm_path"/.git -o -f "$sm_path"/.git
 		then
-			module_clone "$sm_path" "$name" "$url" "$reference" || exit
+			module_clone "$sm_path" "$name" "$url" "$reference" "$depth" || exit
 			cloned_modules="$cloned_modules;$name"
 			subsha1=
 		else

t/t7400-submodule-basic.sh

@@ -963,4 +963,20 @@ test_expect_success 'submodule with UTF-8 name' '
 	git submodule >&2 &&
 	test -n "$(git submodule | grep "$svname")"
 '
+
+test_expect_success 'submodule add clone shallow submodule' '
+	mkdir super &&
+	pwd=$(pwd)
+	(
+		cd super &&
+		git init &&
+		git submodule add --depth=1 file://"$pwd"/example2 submodule &&
+		(
+			cd submodule &&
+			test 1 = $(git log --oneline | wc -l)
+		)
+	)
+'
+
+
 test_done

t/t7406-submodule-update.sh

@@ -729,14 +729,24 @@ test_expect_success 'submodule update properly revives a moved submodule' '
 test_expect_success SYMLINKS 'submodule update can handle symbolic links in pwd' '
 	mkdir -p linked/dir &&
 	ln -s linked/dir linkto &&
-	(
-		cd linkto &&
-		git clone "$TRASH_DIRECTORY"/super_update_r2 super &&
-		(
-			cd super &&
-			git submodule update --init --recursive
-		)
+	(cd linkto &&
+	 git clone "$TRASH_DIRECTORY"/super_update_r2 super &&
+	 (cd super &&
+	  git submodule update --init --recursive
+	 )
 	)
 '
 
+test_expect_success 'submodule update clone shallow submodule' '
+	git clone cloned super3 &&
+	pwd=$(pwd)
+	(cd super3 &&
+	 sed -e "s#url = ../#url = file://$pwd/#" <.gitmodules >.gitmodules.tmp &&
+	 mv -f .gitmodules.tmp .gitmodules &&
+	 git submodule update --init --depth=3
+	 (cd submodule &&
+	  test 1 = $(git log --oneline | wc -l)
+	 )
+	)
+'
 test_done